package A1_二叉树;

public class LC_617合并二叉树_定义新二叉树 {
    public static class TreeNode{
        int val;
        TreeNode left;
        TreeNode right;
        TreeNode(){}
        TreeNode(int val){
            this.val=val;
        }
        TreeNode(int val,TreeNode left,TreeNode right){
            this.val=val;
            this.left=left;
            this.right=right;
        }
    }
    public TreeNode mergeTrees(TreeNode root1, TreeNode root2) {
        if(root1==null)
            return root2;
        if(root2==null)
            return root1;
        TreeNode node=new TreeNode(root1.val+root2.val);
        node.left=mergeTrees(root1.left,root2.left);
        node.right=mergeTrees(root1.right,root2.right);
        return node;
    }
}
